Collapsible salvage device



May 31, 1960 M. M. CUNNINGHAM COLLAPSIBLE SALVAGE DEVICE 2 SheetsSheet 1 Filed Sept. 8, 1958 UODDODUUDUDUOUDDD UDUUDDDUD UDDDDDDDD ATTORNEY May 31, 1960 M. M.- CUNNINGHAM 2,938,489

COLLAPSIBLE SALVAGE DEVICE Filed Sept. 8, 1958 2 Sheets$heet 2 IN V EN TOR. MAR/0W M CU/V/W/VY/A/f ATTORNEY United States Patent 0,.

2,938,489 COLLAPSIBLE' SALVAGE DEVICE Marion M. Cunningham, Providence, R.I., assignor to United States Rubber Company, New York,'N.Y., a corporation of New Jersey Filed Sept. 8, 1958, Ser. No. 759,761

1 Claim. (Cl. 114-54) This invention relates to the raising of sunken ships or other objects by the use of inflatable bags to create sufiicient buoyance and, more specifically, to an improved construction for such inflatable bags.

The use of collapsible and inflatable bags or balloons is well known in the field of marine salvage. A type of bag suggested for this use is shown in U.S. Patent No. 2,508,800, and another type is shown in U.S. Patent No. 2,413,313.

These prior devices all required the use of sling lines or other means for applying the load to the bag and the use of a complicated network of lacing ropes and shroud lines, together with the necessary air supply lines and hauling lines, which would normally result in entanglements and other complications in actual underwater use.

The object of the present invention is to avoid these complications and to provide a more practical and efficient device for performing such salvage operations. A further object is to construct a suitable inflatable bag which can be used without the previously required network of shroud lines and suspension ropes. A still further object is the construction of such a suitable inflatable device in which the lifting loads can be carried by the walls of the device' directly. A still further object is to construct a bag the walls of which will maintain an optimum and preferred shape at all degrees of inflation during the salvaging operations.

In accordance with these objects I have invented an improved collapsible and inflatable marine salvage bag suitable for use without the heretofore required shroud or sling lines and having a preferred shape at all levels of inflation. My salvage bag comprises a bag cut from a single sheet of flexible, gas impervious material, closed along one longitudinal edge by rigid clamping means, said rigid clamping means maintaining the inner surfaces of the wall material at said longitudinal edge in parallel relation to each other. The lateral edges of the bag are closed by a plurality of segmented clamps which form a reentrant angle in each of the lateral edges of approximately 165 when the bag is in a deflated condtion. The corners of the bag at the junctions of said rigid clamping means and said segmented clamps are leftopen to provide an unrestricted means of escape for excessive inflation air. Means are provided along said rigid clamping means for attaching the bag to the submerged object.

The invention is illustrated in the accompanying drawings in which Fig. 1 is a side elevational view, partly in section, of my salvage bag in the deflated condition, showing by dotdash lines its contour when fully inflated;

Fig. 2 is a cross-sectional view along line 2-2 of Fig. 1 when the bag is fully inflated, the dot-dash lines indicating the bags shape at various intermediate levels of inflation and also in the deflated condition;

Fig. 3 is a view along line 3--3 of Fig. 1; and

2,938,489 C Patented May 31,1950

Fig. 4 is a view showing a means of using my improved salvage bag in actual marine salvage operations.

Referring to the drawings, I disclose a marine salvage bag 10 formed of a single folded sheet of flexible, gas impervious metarial 11. This material may be preferably a nylon cord fabric coated with a gas imperious substance such as rubber or the like. For very heavy loads a steel mesh fabric could be used, also with a rubber surface coating. Several plies can be used to provide the necessary wall-strength, with the cord angles varied as shown in the cut-away section of Fig. 1.

The folded edge 12 of the bag 10 is the upper edge. This upper edge thus achieves a smooth, rounded shape at all degrees of inflation. (See Fig. 2.) The lower edge 13 of my salvage bag 10 is clamped together by a rigid longitudinal clamp 14. The longitudinal cut edges 15 are fastened together by this rigid clamp 14 so that the inner surfaces of the wall material 11 are maintained in parallel relation to each other. Thus, at the various levels of inflation, the walls of my bag in the region of this loaded edge 13 are always parallel, maintaining the optimum load-carrying shape at all such levels of inflation.

The rigid longitudinal clamp 14 does not extend all the way to the lateral ends 16 of the salvage bag. An opening 17 at each corner is thereby created, so that excessive air or other buoyancy medium may automatically escape from the inflated bag 10 as pressure conditions vary. Thus, although the opening 17 is normally closed, as the buoyancy of the bag 10 causes a sunken object to rise, the excessive air pressure caused by the diminishing external water pressure causes the openings 17 to act as valves when the bag 10 is'over-inflated and allows air to escape from the bag at these corners to compensate for such decreasing water pressure.

The lateral ends '16 'of my salvage bag 10 are closed by a plurality of segmented clamps 18. When the bag is in the deflated condition, these lateral edges are each cut so as to form a reentrant angle of approximately 165 in each such lateral edge. When fully inflated this angle decreases to approximately This is in accordance with the teaching of my copending application, Serial No. 695,961, filed November 12, 1957, for an improved means of closing collapsible cylindrical containers. As is explained in this copending application, this type of lateral edge closure achieves the optimum shape for the wall material 11 in the region of the lateral ends 16 at all degrees of inflation. Thus, the wall material 11 in the region of the lateral ends 16 is substantially wrinkle-free at all levels of inflation, eliminating thereby any undesirable stresses.

A series ofeyes 19 are provided along the external edge of the rigid longitudinal clamp 14 for fastening the salvage bag 10 to the sunken object. Rubber covered steel cables 20 can be looped together under the object to be raised or other means can be provided for attachment of the bags. Fig. 4 shows a means of using these bags in the salvage of a sunken ship, indicating preferred means of rigging inflation lines 21 and placement lines 22.

I have thus invented an improved marine salvage bag which can be used without the necessity of any shroud or other sling lines. By use of the various clamping means described, I have thus achieved a bag the wall material of which carries the lifting loads and also maintains the preferred and optimum shape at all levels of inflation. This bag, simpler and more efficient to use than those heretofore proposed, will make salvage operations of sunken ships and the like considerably easier than in the past and, hence, relatively more successful.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

An inflatable body for use in raising submerged ob jects comprising a bag of flexible, gas impervious material, closed along one "longitudinal edge 'by rigid clamping means which maintain the inner surfaces-of the wgvall material at said longitudinal edge in parallel relation to each other, the opposed lateral edges of said bag being closed by a plurality of segmented clamps which form a reentrant angle of approximately 165 in each of said opposed lateral edges when said bag isin a flattened condition, the corners of said bag at the junctions of said 298854.89 e a r rigid clamping means and said segmented clamps being "left open to provide a means of escape for excessive infiating medium and means provided along said rigid clamping means for attaching said bag to the submerged 5 object.

References Cited ;i;n the jj le of this patent v Y=UJN1FED S ATE P E FS 

